Socket Connect get exception InvalidHttp ResponseCode Exception on iOS with vmess proxy

We face a very strange issue:

on iOS, if we use the Shadowrocket with vmess proxy. then when run socket.connet, always get the error:

Error connecting socket: Exception of type ‘Nakama.Ninja.WebSockets.Exceptions.InvalidHttpResponseCodeException’ was thrown

and the reason seems like the response header is empty.

we also test same proxy with shadowrocket on Android, it works.

seem like only on iOS have this issue. very strange and confused.